RESUMO
BACKGROUND: This study aimed to address the increasing prevalence of cesarean section and the importance of evaluating newborn health through arterial blood gas analysis. Its primary objective was to compare the umbilical cord blood gas levels in newborns delivered through different delivery methods. METHOD: This retrospective descriptive cross-sectional study included singleton pregnancies with a gestational age between 37 and 42 weeks and infants weighing between 2500 and 4000 g. Newborns with an Apgar score of 7 or higher at 1 and 5 min were included. Umbilical cord blood samples were collected from each newborn for blood gas analysis within 60 min after birth. RESULT: The study included 340 neonates, with 170 born via caesarean section and 170 born through vaginal delivery. No significant differences were observed in Apgar scores between two groups. ABG analysis showed that vaginally born neonates had lower pH (7.24 ± 0.08 vs. 7.27 ± 0.07, P < 0.001), PCO2 (P = 0.015), and HCO3 (P < 0.001). Cesarean section neonates had higher oxygen saturation (P = 0.007) and pressure of oxygen (P < 0.001), and less negative base excess (P < 0.001). In the subgroup analysis, neonates whose mothers received epidural anesthesia had lower pH (7.23 ± 0.07 vs. 7.25 ± 0.08, P = 0.021) and more negative base excess (P = 0.026). Other parameters of ABG did not differ significantly between the groups (P > 0.05). CONCLUSION: It has been proven that the mode of delivery, whether it is vaginal or cesarean, as well as the administration of epidural anesthesia during vaginal delivery, have a significant impact on newborns at birth. Newborns delivered vaginally exhibit metabolic acidosis compared to those delivered via cesarean section. Although these differences are statistically significant, they do not have a notable clinical significance, as the average values of the evaluated parameters in both groups fall within the normal range.